Carel MuC2SE, User Manual

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21
µC
2
SE process c030220416
- rel. 2.3 - 17.05.2018
5.6 Analogue outputs
The analogue output Y1 is set-up for the condenser fan and is active if F01 = 1. In systems with hot gas bypass function enabled, the bypass valve is
commanded by the output Y1 (controller) or Y2 (I/O expansion board). See the control chapter.
5.7 Compensation
The compensation can indifferently increase or decrease the value of r01 depending on whether r17 is respectively positive or negative.
r01 varies only if the external temperature (e.g.B3) exceeds r19:
if B3 is over r19 there will be: r01 effective = r01 + (B3-r19)*r17
if B3 is lower than r19: St1 effective = St1
r01
r19
B3
r01+r18
r01-r18
r17=2
r17= +0,5
r17= -0,5
r17= -2
r01_comp
Key
r01_comp
Set point compensation
5.8 Low load
In the systems with reduced water content, a storage tank must be provided, so that there are no continuous and rapid temperature
changes in the cooled water following control intermittence. In this way, the number of compressor hourly switch-ons/offs is limited to an
acceptable number. The storage tank can be eliminated in low load conditions.
Low load condition:
1. only one compressor is active;
2. the compressor is switched off after an operating period less than the value of parameter r28.
r28 therefore represents the minimum operating time of the compressor, below which the low load condition is determined. The compressor will
analyse the low load status every time the compressor is switched off. If already in low load state, the time considered by the controller for the new
analysis becomes r28xr29: r02”.
The low load differential is r29. This parameter represents the new differential considered by the controller during the low load condition. Specifically
r02 is replaced by r29.
Par. Description Def Min Max U.M.
r01 Set-point 12 r13 r14 °C/°F
r17 Compensation constant: 0 = no compensation 0 -5 5 -
r18 Maximum distance from the set-point 0,3 0,3 20 °C/°F
r19 Start compensation temperature 30 -40 176 °C/°F
Par. Description Def Min Max U.M.
r27 Accumulation vessel suppression (low load)
0=Disabled
1=Enabled
2=Do not select
3=Do not select 0 0 3 -
r28 Min. compressor running time for low load 60 0 999 s
r29 Low load differential 3 1 50 °C/°F
evaporator
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